Electric machines such as, for example, motors and generators may be used to generate mechanical power in response to an electrical input or to generate electrical power in response to a mechanical input. Magnetic, resistive, and mechanical losses within the motors and generators during mechanical and electrical power generation cause a build up of heat, which may be dissipated to avoid malfunction and/or failure of the device. One of the limitations on the power output of the electric generators may be the capacity to dissipate this heat.
Cooling stator cases or jackets provide an excellent means for cooling electric motors and generators, such as brushless permanent magnet motors operating at high speeds and driven by fuel-powered engines to generate electrical power. Electric motors and generators generate considerable heat and require an efficient cooling system. Motors and generators are often equipped with a means for cooling, formed of a cooling jacket provided with grooves or passages built into the motor/generator housing. Circulating oil or water, or even air through the grooves or passages provides cooling to the motors and generators.
It is common practice in machining applications to machine spiral grooves into a metal part. Machined spiral grooves into a housing have been shown to work well to remove the necessary heat from these components, however machined spiral grooves are expensive to cut in a production environment.
In a patent application to Burjes et al. (2007/0268464 A1), a method of making a motor/generator cooling jacket is disclosed. A hollow cylindrical housing is cast with an outer peripheral surface and an annular axially facing end surface, a plurality of grooves formed in the outer peripheral surface and a radial lip at one end. The Burjes et al. patent application also teaches inlet and outlet ports drilled through the end surface to communicate with the grooves, and sealing recesses and o-ring seals integrated for sealing. However, the prior art process does not provide mechanisms to protect from pressure drop across the channels.
Further, the Burjes invention teaches a non-continuous flow path, which may require the cooling fluid to make 180-degree turns and flow in opposite directions. This non-continuous circulation path may further contribute to inconsistent and inefficient means for equally cooling the stator, and may lead to a less efficient system potentially causing a higher than desired pressure drop across the entire path of the fluid.
The present disclosure is directed to overcoming one or more of the issues set forth above.